Disconnectably connectable peripheral devices add great flexibility to computer systems because for example, one peripheral device can be easily shared among several computers. A well known such shareable device is the finger-sized USB (Universal Serial Bus) connectable Flash memory device (sometimes referred to as a Jump drive or Thumb drive or Memory stick). Users can easily hot-plug a USB memory stick into a USB socket of a first computer (e.g., desktop, laptop, tablet, etc.) for automated plug and play of on-stick music or execution of an in-stick application program or they can easily move or copy files between their hard drives and the USB memory stick. Users can easily disconnect the memory stick from the first computer, carry it over to a second computer, reconnect the stick into the USB socket of the second computer and again transfer files, play music or execute an in stick application program.
One of the background operations that make quick and easy plug-and-play possible for USB connectable peripherals is a standardized USB hot-plug connection-making protocol. When a USB device is plugged into a USB socket, a USB protocol-compliant program automatically detects the plug-in event and automatically inquires as to the device type and class of the plugged-in peripheral. Examples of device typing classes include device class enumerators such as: LIBUSB_CLASS_MASS_STORAGE (e.g., for flash memory sticks); LIBUSB_CLASS_AUDIO (e.g., for plug-in audio devices); and LIBUSB_CLASS_PRINTER (e.g., for plug-in printers). Once the connection-making procedure determines the device class and other attributes of one or more newly attached USB devices it knows how to deal with each. For example it may automatically load appropriate device interfacing software drivers for each of the self-identifying USB devices. This kind of automated, plug-and-play disconnectable connection making brings great flexibility. However it also opens up security holes.
It is to be understood that this Background section is intended to provide useful introductory information for understanding here disclosed and novel technology. As such, the Background section may include ideas, concepts or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to corresponding invention dates of subject matter disclosed herein.